Is CVE-2021-28804 actively exploited?

No active exploitation of CVE-2021-28804 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2021-28804 be exploited remotely?

Yes. CVE-2021-28804 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2021-28804?

CVE-2021-28804 has a CVSS score of 9.8 (CRITICAL).

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CRITICAL

CVE-2021-28804

CWE-78Published: July 1, 2021· Updated: Jun 17, 2026

9.8

CVSS v3.1

Official Description

A command injection vulnerabilities have been reported to affect QTS and QuTS hero. If exploited, this vulnerability allows attackers to execute arbitrary commands in a compromised application. This issue affects: QNAP Systems Inc. QTS versions prior to 4.5.1.1540 build 20210107. QNAP Systems Inc. QuTS hero versions prior to h4.5.1.1582 build 20210217.

NVD Source

Technical Analysis

CVE-2021-28804 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 9.8.